A single system could perform any FSW or FPW operation.
A proposed system of tooling, machinery, and control equipment would be capable of performing any of several friction stir welding (FSW) and friction plug welding (FPW) operations. These operations would include the following:
- Basic FSW;
- FSW with automated manipulation of the length of the pin tool in real time [the so-called auto-adjustable pin-tool (APT) capability];
- Self-reacting FSW (SRFSW);
- SR-FSW with APT capability and/or real-time adjustment of the distance between the front and back shoulders; and
- Friction plug welding (FPW) [more specifically, friction push plug welding] or friction pull plug welding (FPPW) to close out the keyhole of, or to repair, an FSW or SRFSW weld.
Prior FSW and FPW systems have been capable of performing one or two of these operations, but none has thus far been capable of performing all of them.
The proposed system would include a common tool that would have APT capability for both basic FSW and SR-FSW. Such a tool was described in “Tool for Two Types of Friction Stir Welding” (MFS-31647-1), NASA Tech Briefs, Vol. 30, No. 10 (October 2006), page 70. Going beyond what was reported in the cited previous article, the common tool could be used in conjunction with a plug welding head to perform FPW or FPPW. Alternatively, the plug welding head could be integrated, along with the common tool, into a FSW head that would be capable of all of the aforementioned FSW and FPW operations. Any FSW or FPW operation could be performed under any combination of position and/or force control.
This work was done by Robert Carter of Marshall Space Flight Center. For further information, access the Technical Support Package (TSP) free on-line at www.techbriefs.com/tsp under the Manufacturing & Prototyping category.